I found this site, run by the University of Hawaii Sea Level Center which shows recent sea level deviations at certain locations across the world compared to the 1993-1995 mean. Not all of the locations are up and running, but if you click on one that is it will show you the sea level height anomaly trend going back 10, 20, 25 years back or so, depending on when the site was initially started up and running. I have seen a lot of conflicting opinions on the comment section of this blog in regards to this subject.

As you can see, the deviations are quite variable. Most of the higher sea levels compared to the 1993-1995 mean were located in the western Pacific, western Atlantic and around Australia. The lower deviations were concentrated off of Scandinavia and the west coast of North America.

The cool phase of the Pacific Decadal Oscillation (PDO) has been at least partly responsible for the warming of surface waters over the northwestern/western Pacific. The warmer waters have caused a thermal expansion of the water and a resulting sea level rise. How much of the rise is due to that? I do not know. Here is a link to the latest global sea surface temperature anomalies.

A previous report in June from ScienceDaily suggested that ocean temperature and associated sea level increases between 1961-2003 were 50% larger than estimated in the 2007 IPCC report. Sea levels rose by 1.5 mm per year from 1961-2003 or a total of 2.5 inches in during the 42-year span.

Hurricane Katrina Flood damage in New Orleans, LA. Image courtesy NOAA.

Joel Achenbach of the Washington Post wrote an excellent article Sunday about how global warming is being overblamed in regards to specific natural disasters. From what I see, a lot of this is being created by a thirsty, big headline seeking news media. Some global warming advocates are also guilty of this rush to judgement.

I am not saying that global warming is completely off the hook when it comes to some of these particular disasters, but there is just not nearly enough information (data) out there to link the two with certainty. Far from from it, at this early point in time. Ten, twenty, a hundred years from now maybe that will change, but who knows.

Achenbach uses the Katrina and Iowa floods as prime examples of the quick-to-blame global warming rational. (Read the article here)

Kerry Emanual, a climatologist from MIT and a subject of at least one of my previous blogs was quoted in the article, stating "Global warming increases the probability of floods and strong hurricanes and that is all you can say." Makes sense to me.

Achenbach seems to zero in on the rapid growth of human population as the main culprit to many of these disasters. What do you think?

Also, Ken Clark, our western forecast expert, who also regularly blogs here at AccuWeather.com voices his opinion on a new plastic bag bill in California. You can read it here.

The United States and Canada at night. Image courtesy of NASA.

Thinking that this would be an excellent conversation starter, I was asked to post a link to the recently released "first draft" of the U.S. Climate Change Science Program's "Global Climate Change Impacts in the United States".

Since this is a first draft, we are asked not to cite or quote from the document. In addition to listing the expected impacts of climate change in the U.S., the document also goes over some of the things that society can do to respond to climate change and how we can adapt.

This document was prepared by an expert team of scientists and supporting professionals. Much of the information is based on existing, published peer-reviewed data found in scientific journals. The IPCC conclusions are also used.

The PDF is fairly long (give it a minute or so to download), but it is easy to read with lots of graphics. I do not know when the "final draft" will be made available.

Here is the link to the U.S. Climate Change Science Program site.

The public can review this draft and submit comments before the August 14th deadline. Here is that link.

Mount Rainier, Washington.

A new study from the University of Washington suggests that there is no clear evidence that human-induced global warming has caused a drop in 20th century snow levels and that the volcanic, mountain chain could enjoy a delay in the future effects of global warming, according to an article from the Seattle Times.

Here is a link to the powerpoint presentation of the study. By the way, the first picture of the man skiing up to the roof of that building was the same hotel I stayed at during a visit several years ago on Mount Rainier. I am pretty sure that is the Paridise Hotel. When we went in July there was still many patches of snow up to a foot deep all around the grounds of the hotel.

Cliff Mass, a University of Washington meteorologist and co-author of this study says that studying the snowpack trends depends greatly on which years are examined. Mass and colleagues tried to estimate snowpack before the 1950's, a decade where snow levels were unusually high and the reason why we see a greater than 30% drop off in snow pack over the second half of the century when you use that decade as the starting line.

Mass and his team used a measurement that did exist before the 1950s: The amount of water that flowed down streams as snow melted. The team determined that the drop in snowpack from the 1930's through present time was 23%. (The 1930's in the U.S. was a warm decade, but I do not know if that was the case in the Cascades. It would be nice to know what the percentage drop was when you start out in the 1900's, 1910's or 1920's as well.)

Mass and colleagues say that many of these changes in snowpack are attributable to shifting weather patterns driven by the Pacific Ocean, which is what we heard from the Mount Shasta glacier report I blogged about recently.

The team also noted that computer models predict that the northeast Pacific will warm more slowly than most of the world's oceans, keeping the average rain/snow level from gaining altitude
too quickly.

Not so fast!

Alan Hamlet, a University of Washington hydrologist, who co-authored a study on snowmelt hydrology in the mountainous West back in 2005 disagrees with Mass. Hamlet says the snowpack trends during the second half of the century are consistent with rising temperatures which are tied to global warming. He also criticizes some of the statistical analysis of the new study co-authored by Mass.

You can read more about this story here..

The Arctic has now reached the peak of the summer melt season and scientists now predict that the 2008 sea ice extent will most likely not break the record low minimum set in 2007, but it will still end up well-below normal with a minimum sea-ice extent less than 2005, which right now stands as the second lowest extent on record.

The latest graph of the Arctic sea ice extent, courtesy of the NSIDC. Note: there has been a more sharp drop over the past several days. It will be interesting to see if that trend continues.

Scientists now give the chances of a new record sea-ice extent minimum being set in 2008 at 8%, according to the ScienceDaily article. But, a lot of the sea ice is still quite weak and thin and and a sudden, rapid melt off over the next month still cannot be totally ruled out.

The Graph below shows the latest Arctic sea ice extent forecast from the NSIDC on July 30th. Remember, this forecast was issued right before the latest downturn is sea ice extent.

The future of sea ice extent and thickness greatly depends on the weather (wind, clouds and air temperature) and scientists are studying these factors and utilizing new computer models to better predict the eventual outcome of the sea ice in the Arctic over the coming years.

Here are the July 2008 global temperature anomalies as measured by satellite using microwave soundings. The data is provided by Remote Sensing Systems (RSS) using MSU and AMSU data. The below image shows the July temperature anomalies across the globe for the lower troposphere in degrees Kelvin. The reds and yellows indicate warmer-than-normal temperatures during the month of July, while the blues indicate cooler-than-normal conditions.

As you can see, the warmest temperatures compared to normal were found over central South America. Other above-normal areas included Atlantic Canada and eastern Russia.

Temperatures were clearly below-normal over Alaska and the Yukon Territory, aso over the far southern oceans.

Here are some specific numbers (temperature anomalies) for July.....

Global land and sea combined: +0.147 degrees Kelvin, making it the warmest month compared to normal since October of 2007, but still cooler than the past three July's.
Northern hemisphere: +0.258 K
Southern hemisphere: +0.031 K
Continental U.S.: +0.340 K

Acknowledgement

MSU/AMSU data are produced by Remote Sensing Systems and sponsored by the NOAA Climate and Global Change Program. Data are available at www.remss.com.

In this week's Headline Earth video, host Katie Fehlinger interviews NOAA oceanographer Phyllis Stabeno. Stabeno says that despite global warming, the Arctic will never be a "warm" place, but the loss of sea ice at certain times of the year will impact more animals than just the polar bear.

The eye of Hurricane Wilma from space.

A new study by researchers from NOAA goes even further in the latest argument that rising ocean temperatures due to global warming will not produce more hurricanes.

Going back to 1878 data, storm numbers have supposedly increased at a rate of 3.8 per century, but the pre-World War II data has many inaccuracies, since the numbers were based on ship observations.

In order to correct for these inaccuracies, Gabriel Vecchi and Thomas Knutson of NOAA tried to superimpose known storm tracks from 1965 to present over known ship tracks from 1878-1965. The duo determined that ships indeed missed many storms, especially during the early years (19th century) compared to the 1960's and that those early ships probably missed about 1/3 of the storms.

Adding that 1/3 to the official record yields a nearly flat trend in storm frequency from 1878-2006 despite a rise in ocean surface temperature of 0.7 celsius.

This study was published in the Journal of Climate.

A USGS crew evaluating forest thinning one year after a late-season burn.

The current policy of wildfire management by supressing small fires is causing less carbon to be stored in trees, according to a new study from the University of California.

The research team, led by Michael Goulden found that during the period from the 1930's to the 1990's mid-altitude conifer forests increased in area by 34%, but contrary to the conventional wisdom that more trees mean additional carbon storage- they found that the amount of stored carbon actually diminished by 26% during the same period, according to the Scientific American article.

Current wildfire policy is to stop more ground blazes, which is preserving more and more small-sized trees which hold much less carbon compared to bigger, more mature trees.

Potential Solution?

Preserving the heftier trees is the easy solution to augmenting carbon storage and allowing them to play their ecological roles, says Nathan Stephenson, an ecologist from the U.S. Geological Survey.

As the climate changes and puts stress on plant life, Stephenson says, it is probably better for the forest to get back to the way it used to look: thinner and less crowded. In fact, the national parks of the Sierra Nevada Mountains, with which he closely works, already use prescribed fire to thin forests. Burning or cutting down trees will release some carbon into the atmosphere. But at least, Stephenson notes, “you reduce the chance that you’re going to lose all [the carbon] in a catastrophic wildfire.”

Note: The previous two paragraphs are exerpts from the Scientific American article.

As I noted last week, the National Sea Ice Data Center (NSIDC) has now confirmed that the pace of sea ice loss in the Arctic basin sharply quickened over the last ten days. That latest updated graph below does seem to indicate that that the trend over the last two days might have begun to resume a more normal trend, but I think they will need another week of data to confirm that.

The big question was why did we see this sudden drop off of ice coverage? According to the NSIDC, a series of strong storms helped trigger warm, southerly winds which broke up thin ice in the Beaufort and Chukchi Seas. Looking at the sea level pressure map below for Aug 6th, 2008, you can see the large area of low pressure extending north from Siberia, the counter-clockwise flow around the low pressure produced the stronger southerly winds, especially over the Chukchi Sea. You can also see the large area of high pressure centered over Greenland. The clockwise flow around the high also produced southerly winds up through far northern Canada. By the way, that same pattern forced the chilly air that you normally see in northern Canada much farther to the south, resulting in the unusually cool and wet pattern that we have been seeing over eastern Canada, the Great Lakes and the Northeast U.S.

Northwest Passage opening up again

Just like last year, the famous Northwest Passage is opening up once again. Check out the August 10th satellite-microwave image of that region below. According to the NSIDC, just a small section of sea ice was blocking the route as of a few days ago, but that was expected to melt off fairly quickly.

Just FYI, here is the latest Arctic region sea-ice concentration map from the University of Bremen (Aug 12th)....